bgpd: fixes for ipv4 mapped ipv6 address #16439
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
When IPv6 prefixes are sent over an IPv4 session, the UPDATE is sent
with a link-local nexthop as global nexthop instead of a IPv4-mapped
IPv6 address. If the peer interface has no IPv6 address, routes are
not installed.
Seen with bgp_nexthop_mp_ipv4_6 topotests on step2:
> root@r2:/# vtysh -c 'show bgp ipv6 fd00:100::/64 json' | jq .
> {
> "prefix": "fd00:100::/64",
> "paths": [
> {
> "nexthops": [
> {
> "ip": "fe80::449a:f8ff:fe67:1f93",
> "hostname": "r1",
> "afi": "ipv6",
> "scope": "global",
> "metric": 0,
> "accessible": true
> },
> {
> "ip": "fe80::449a:f8ff:fe67:1f93",
> "hostname": "r1",
> "afi": "ipv6",
> "scope": "link-local",
> "accessible": true,
> "used": true
> }
> ],
> }
> ]
> }
Now:
> root@r2:/# vtysh -c 'show bgp ipv6 fd00:100::/64 json' | jq .
> {
> "prefix": "fd00:100::/64",
> "paths": [
> "nexthops": [
> {
> "ip": "::ffff:172.16.0.1",
> "hostname": "r1",
> "afi": "ipv6",
> "scope": "global",
> "metric": 0,
> "accessible": true
> },
> {
> "ip": "fe80::3842:28ff:fe90:f815",
> "hostname": "r1",
> "afi": "ipv6",
> "scope": "link-local",
> "accessible": true,
> "used": true
> }
> ],
> }
> ]
> }
Note that the link-local is still preferred over the global address.
Fixes: 25995695f5 ("bgpd: set ipv4-mapped ipv6 for ipv4 with ipv6 nexthop")
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
Fix nexthop resolution of ipv4-mapped ipv6 nexthop addresses. Fixes: 5dd731a ("bgpd: prefer link-local to a ipv4-mapped ipv6 global") Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
Replace IPv4-mapped IPv6 at update forwarding because the peer may not be able to create a route with the IPv4-mapped IPv6. Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
Test that a IPv4-mapped IPv6 is sent from a peer that has no global IPv6 address. Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
louis-6wind
force-pushed
the
fix-ipv4-mapped-ipv6
branch
from
1790abb to
d618436
Compare
louis-6wind
changed the title
|
ci:rerun |
|
should there be a knob to change the behavior in case someone wants the link local address as the forwarding address? |
|
Looks like the topo isn't passing -- |
This was referenced Aug 14, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
fixes for ipv4 mapped ipv6 address. See individual commit logs